twinject (touhou windows injector) is an automated player for the bullet hell games from the TouhouWiki:Touhou Project. Instead of using computer vision techniques to extract data from the game, a DLL is injected and the relevant game data is directly extracted through trampolined functions. twinject's first goal is to expose game information and APIs to interact with the game.
For the unaware, bullet hells are a category of Shoot 'em Up video games where the player controls a ship, which must dodge large numbers of obstacles and destroy large numbers of enemies. In the demonstration videos, the fast moving projectiles are the obstacles which must be dodged - if the player hits any of these projectiles they die immediately. The player itself also fires projectiles, which damage enemies. Props to ZUN for making games that people still play 20 years later.